This invention relates to turbomachinery and more particularly to an improved type of turbomachinery which is a unique turbine-compressor-ejector device having unique structural features and performance and which is capable of use in a wide variety of various and diverse cycles.
It is known in the art to use turbines and compressors or turbine-compressor combinations in various cycles, see for example my earlier issued U.S. Pat. Nos. 3,570,261; 3,805,540; 3,869,351; and 4,023,946 and my copending United States application Ser. No. 606,790, filed Aug. 22, 1975.
As is known in the art, a turbine is a device which uses fluid at a relatively high pressure and usually at a relatively high temperature to convert energy to work. The output of the turbine is fluid at a lower pressure and which is cooler than the input. The difference in temperature is directly related to the work output and may be expressed in terms of the temperature difference times the specific heat and mass flow of the fluid, the product representing the power output.
In the case of a compressor, the input is a fluid at a relatively low pressure and usually at a relatively low temperature. The output is at a pressure and temperature higher than the input and the amount of work required again is related to the difference in temperature and may be expressed in terms of the temperature difference times the specific heat and the mass flow, the product representing the power input.
Also known in the art is a device called an ejector, in which a high pressure source fluid is used to pump low energy low pressure fluid. In the process of operation, the pressure of the high pressure source fluid is decreased and the pressure of the low pressure fluid is increased to exit pressure. In most instances an ejector is inefficient although if the low pressure fluid is at an extremely high temperature it may be possible to obtain a uniform velocity immediately in front of the ejector tube and this may be a high efficiency system.
In the case of turbomachinery, e.g. turbines, compressors, and turbocompressor combination, the efficiency of small equipment, i.e. equipment operating at relatively low Reynold's Numbers for a turbine is about 50% while that of a compressor is in the range of 35% to 42%. As is well known in turbomachinery, the Reynold's Number is equal to the tip speed of the machine times the diameter of the wheel divided by kinematic viscosity of the fluid. Thus, in systems employing relatively low Reynold's Number turbine-compressor combinations, the overall system efficiency is in the range of 17.0% to 21%.
In a compressor-turbine combination, there are disc friction losses due to the shearing action between the wall and the rotating part. These friction losses occur at four places, the front and back of each wheel of the compressor and turbine. Moreover, a compressor usually has a diffuser, used to convert kinetic energy to potential energy by slowing the velocity of the fluid leaving the wheel. In effect, the fluid leaving the wheel is at a high tangential velocity and the diffuser functions to convert the high velocity to high pressure at relatively low velocity. Thus, the presence of a diffuser represents one of the major single losses in overall efficiency in a compressor.